Solitary extramedullary plasmacytoma of the gingiva-A case report with literature review

Extramedullary solitary plasmacytoma (EMP) is a plasma cell neoplasm involving the soft tissues without the involvement of the bone marrow. In this case report, we present an isolated soft tissue growth on the lingual gingiva of the left mandibular canine-premolar region diagnosed as EMP based on clinical, histological, and laboratory results. Orthopantomogram and occlusal radiographs showed no osteolytic lesions. Hematoxylin and Eosin staining showed sheets of inflammatory cells, predominantly atypical plasma cells with varying degrees of differentiation showing features of pleomorphism, and multinucleated giant cells with intervening collagen fibers. Positive immunoreactivity for CD56, CD138, and kappa light chain restriction were observed. Serum protein electrophoresis demonstrated an increase in IgA levels and immunofixation electrophoresis confirmed the presence of the M band in the IgG and kappa lanes, indicating monoclonal gammopathies. Based on the above findings, the case was diagnosed as EMP; the consultant pathologist, however, recommended excluding multiple myeloma.